Mold assembly for forming protrusions on base field of the invention

ABSTRACT

A mold assembly includes a bottom mold having a plurality of concavities defined therein and a top mold which includes a recess defined in an underside thereof so that the bottom mold is engaged with the recess. The length of the recess between two insides is less than a length of the bottom mold so that the bottom mold is snugly engaged with the recess by proper scalability of the metal material of the top and bottom molds. A plurality of through holes are defined through the top mold and located corresponding to the concavities. Forming material is pouted into the concavities via the through holes.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a mold assembly for forming protrusions on a base and includes a top mold and a bottom mold which is easily and precisely matched to the top mold.

(2) Description of the Prior Art

A conventional method form making outsole for shoes generally uses two molds between which concavities are defined and forming material is poured into the concavities, a base material is then connected to the forming material in the concavities so as to form an outsole made by the base material with protrusions made by the forming material on the outsole. In order to reduce surplus on the outsole, the mold assembly includes a top mold and a bottom mold which is matched with the top mold. The smaller the gap between the two molds, the less the surplus is produced. An electro-magnetic clamp is used to firmly connect the top and bottom molds to reduce the gap, or a permanent magnet is used to suck the top and bottom molds together. Both of the top and the bottom molds have to be made by heavy metal material so as to be sucked by the magnetic force and the heavy metal material and the huge permanent magnet are costly. If the molds assembly is made to be thinner and a less powerful of the magnet is used, the shapes of the concavities are limited within the thin molds. Besides, the products are difficult to be removed from the mold assembly.

The present invention intends to provide a mold assembly which includes a top mold and a bottom mold which includes a mold body protruding from a base, and the top mold includes a recess in which the mold body is received. The top mold and the mold body are made by proper metal material which includes certain degree of scalability so that the top mold and the mold body of the bottom mold can be matched precisely to minimize the surplus on the product.

SUMMARY OF THE INVENTION

The present invention relates to a mold assembly which comprises a bottom mold having a plurality of concavities defined therein and a top mold which includes a recess defined in an underside thereof so as to receive the bottom mold therein. The length of the recess between two insides is slightly less than a length of the bottom mold so that the bottom mold is snugly engaged with the recess by the scalability of the metal material of the top and bottom molds. A plurality of through holes are defined through the top mold and located corresponding to the concavities so that the forming material can fill the concavities and the through holes.

The primary object of the present invention is to provide a mold assembly which does not use magnetic force to match the top and bottom molds and the top and bottom molds are snugly matched to each other to minimize the surplus.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view to show the mold assembly of the present invention;

FIG. 2 is a cross sectional view to show the mold assembly of the present invention;

FIG. 2A is an enlarged cross sectional view to show the first and second guide inclined surfaces defined in the top and bottom molds;

FIG. 2B is an enlarged cross sectional view to show the through holes in the top mold and the concavities in the bottom mold;

FIG. 3A shows the forming material is poured in the concavities via the through hole;

FIG. 3B shows the forming material is poured in the through hole;

FIG. 3C shows a base part is put on the top mold and connected with the forming material in the through holes;

FIG. 4 shows protrusions formed on the base part, and

FIG. 5 is a cross sectional view to show another embodiment of the mold assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1, 2, 2A and 2B, the mold assembly 1 of the present invention comprises a bottom mold 10 which includes a base 11 and a mold body 12 extends from a top of the base 11. A plurality of concavities 13 are defined in a top of the mold body 12. Each of the concavities 13 includes a U-shaped inner end. A first guide inclined surface “C” is defined along an edge of each top side of the mold body 12.

A top mold 20 includes a recess 21 which is defined by a skirt portion 202 extending from an underside of the top mold 20. A plurality of through holes 22 are defined through the top mold 20 and located corresponding to the concavities 13. The skirt portion 202 is a rectangular part on each of sides of the top mold 20 and a second guide inclined surface “C1” is defined along an edge of an inside edge of the skirt portion 202. The length “t” of the recess 21 between two insides is slightly less than a length “T” of the mold body 12 of the bottom mold 10 so that the bottom mold 10 is snugly engaged with the recess 21 by scalability of the metal material of the top and bottom molds 20, 10. The top mold 20 and the bottom mold 10 are made by aluminum alloy or copper alloy.

When matching the top and bottom molds 20, 10, the first and second guide inclined surfaces C, C1 guide the mold body 12 to be engaged with the recess 21 easily and the mold body 12 is snugly engaged with the recess 21 so that the surplus can be minimized. The underside of the skirt portion 202 is rested on the top surface “A” on the base 11 and located around the mold body 12.

As shown in FIGS. 3A to 3C, the forming material “B” is poured into the concavities 13 via the through holes 22. When the forming material “B” in the concavities 13 is about to condensate, another forming material or the same forming material “B” is poured into the through holes 22 and is connected with the forming material “B” in the concavities 13. The color of the forming material in the through holes 22 can be different from that in the concavities 13 when needed. When the forming material “B” in the through holes 22 about to condensate, a base part 30 is put on the top of the top mold 20 and connected with the forming material “B” in the through holes 22. It is noted that the width or inner diameter of the through holes 22 is larger than that of the concavities 13, so that the product with protrusions 40 on the base part 30 is easily removed from the mold assembly 1 by pulling it upward as shown in FIG. 4. The forming material “B” can be plastic, rubber, Polyurethane, Polyvinyl chloride and Epoxide resin. The base part 30 can be made by Polyurethane, Polyvinyl chloride, Thermal Plastic Rubber, Nylon, leather, fabric, Thermoplastic fiber, or even paper board.

As shown in FIG. 5, each of the concavities 13 can include inclined inner periphery such as a cone-shaped inner end 131 or any other shape to provide different variety of outer appearances to the protrusions 40.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A mold assembly comprising: a bottom mold having a plurality of concavities defined therein, and a top mold including a recess defined in an underside thereof and the bottom mold being engaged with the recess, a length of the recess between two insides being less than a length of the bottom mold so that the bottom mold being snugly engaged with the recess, a plurality of through holes defined through the top mold and located corresponding to the concavities.
 2. The mold assembly as claimed in claim 1, wherein the bottom mold includes a base and a mold body extending from a top of the base, a first guide inclined surface is defined along an edge of each top side of the mold body, the recess of the top mold is defined by a skirt portion extending from the underside of the top mold, the skirt portion is a rectangular part on each of sides of the top mold, a second guide inclined surface is defined along an edge of an inside edge of the skirt portion, the first and second guide inclined surfaces guide the mold body to be engaged with the recess.
 3. The mold assembly as claimed in claim 2, wherein each of the concavities includes a U-shaped inner end.
 4. The mold assembly as claimed in claim 2, wherein each of the concavities includes a cone-shaped inner end.
 5. The mold assembly as claimed in claim 2, wherein each of the concavities includes inclined inner periphery.
 6. The mold assembly as claimed in claim 2, wherein the top mold and the bottom mold are made by metal material.
 7. The mold assembly as claimed in claim 6, wherein the top mold and the bottom mold are made by aluminum alloy or copper alloy. 